Wall-board enamel and method of applying the same



Feb. 17, 1931. 1,793,437

wALL BOARD ENAMEL 'AND METHOD oF APPLYING THE SAME J. w. COWELL Filed Dec.

@Horneqs Patented Feb. 17, 1931 UNITED STATES JOHN W. COWELL, OF GRAYLING, MICHIGAN WALL-BOARD. ENAMEL AND METHOD OF .APPLYING THE Application led December 16, 1927. Serial No. 240,475.

My invention relates to protective coatings for Wallboard and like sheet materials, and mymain object is to produce a coating of this kind in the nature of an enamel of a durable 5 character.

A further object of the invention is to produce an enamel which produces a hard and vitreous nish, which is waterproof and can stand hard usage.

Astill further object of the invention is to lend the. novel enamel a degree of lexi bility which will resist cracking or checking as the wallboard is handled, cut or nailed.

Another object or", the .invention is to compound the novel enamel in a manner to permit of its preparation in various colors and lill imitations ot stone, graining, marble veining and other effects.

A final but nevertheless important object of the invention is to apply the novel enamel by a unique method, whereby to assure the perfect coating of the same upon the wallboard.

With the above objects in view and any others that may suggest themselves in. the specication and claims to follow, the composition of the novel enamel will iirst be' treated, reference being later made to the accompanying drawing in which the method of applying the enamel to the wallboard is illustrated,

To compound the enamel, I provide the following ingredients: Magnesite, l part by volume; iinely divided silica, l part by volunie; finely divided asbestos, 1 part by volu ume; i'inely divided hard Wood sawdust, 2 parts by volume; magnesium chloride, 22 t0 26 degrees Baume, in determinate quantity.

In compounding the above ingredients, the first step is to mix the asbestos with the sawdust and moisten the same with the magnesium chloride. But enough of the chloride is used to thoroughly moisten the solids without excess of liquid residue. The balance ot the solid ingredients are then added to the aforesaid mixture and agitated while thin with more of the magnesium chloride, so that the resulting mixture will be of a thick 5 creamy consistency and uniform in' texture.

The enamel is now ready for use.

In order to applyfthe novel enamel, I use a Yunique method whereby I may secure an even and perfect coatin Thus, I pour a thin layer of the enamel into a shallow mold having the appearance o' apan or tray. I have illustrated this mold in perspective in Figure l of the accompanying drawing, the bottom being indicated at 5, the wall at 6 and a reinforcing marginal flange` at 7. Con structed in this manner, the mold may be formed reasonably large without becoming subject to warping or distorting tendencies, since the wall 6 and flange 7 strengthen the mold to a suiiicient degree.

The depth of the mold is so dimensioned as to accommodate a suicient layer of the enamel and provide only so much space above this layer as to accommodate the thickness of the wallboard. Thus, the height of the enamel layer is indicated in Figure l by the inely dotted lines, and it may be assumed that the mold is only so much higher as tol receive a sheet of wallboard o1" standard or predetermined thickness.

Before the wallboard is laid in the mold, I span the latter near the ends with cross rails 8, each indicated in the plan view of Figure 2, then depositing the wallboard 9 lipon.

these rails.'v The longitudinal section of Figure 3 also illustrates this arangement, and it will be noted that the wallboard is marginally short of the mold walls by a narrow space.

The wallboard is now supported in close proximity to the enamel, and in order to coat the underside thereof', I place a medial cross bar 10 upon the wallboard in the position indicated by finely dotted lines in Figures 2 and 3. This cross bar is suiciently heavy to depress theI medial portion of the Wallboard to the extent of dipping its under side in the enamel, as clearly indicated'in Figure 4. The Wallboard is, ot course, suiiiciently exible to permit this action, and it may be assumed that the medial portion of the same has receiveda complete, transverse coating of the enamel. In order to coat the balance of the under surface of the wallboard, I work toward the the ends thereof by gradually moving or shifting the outer cross rails 8 in an outward direction so as to progressively lower process of application, I am able to impart the elevated portions of the wallboard into contact with the enamel. This method of coating the wallboard permits ,the enamel to gain upon the surface of the wallboard gradually and displace the air under the wallboard evenly, so that no air globules or pockets may be caught in the enamel to prevent the thorough coating of the same upon the surface of the wallboard. The gradual coating of the enamel thus eliminates the possibility of crust or shell-like formations in the enameled surface after the same has dried, which formations may chip or peel of to expose the original wallboard surface and defeat the purposes of my enamel.

It will thus be seen that by my gradual a full and uniform coating to the surfacek of the wallboard. Further, the nature of my mold enables the enamel to rise about the edges of the wallboard as the same has been fully lowered into the enamel, so that the edges receive the coating as well as the under surface. Each piece of wallboard is thus a finished piece all around.

\- In contemplating the properties of the novel enamel, the' individual advantages of the ingredients were considered. Thus, the sawdust is a good ller, and has flexibility;

the asbestos is also an incidental filler and has plastic pro erties; the magnesite is a cement bond the silica is a void filler and strengthening agent, and it im arts a hardness to the product after it has ried as well as a white color; and the magnesium chloride is the vehicle and medium for the merging of the solids and the solution of the magnesite cementto form the resulting semi-liquid prod- When the enamel has dried it has a lassl like or vitreous finish, is waterproo and weather-proof and 4may be washed, scoured or otherwise cleaned without danger of damage to the finish. The coating is hard yet flexible, so that it will not check, crack or break when the wallboard is iexed or when nails are driven nearthe edges to fasten the same. The texture of the enamel gives it a marked tenacity, which is evident when the wallboard is sawed or otherwise cut, such treatment being received by the enamel smoothly and without chipping or cracking in any manner. The enamel may be treated with colors and mixtures to give it a finish of imitation marble, wood graining, a stone effect or veining efects. In fact the enamel may be prepared to suit any desired condition or effect with ease without the loss of its aboveenumerated properties or advantages. It will,

also be apparent that theingredients I am using are relatively inexpensive, so that I am providing an enamel which may be produced at low cost and may therefore be given a wide use. Also, the use of the novel enamel need not be restricted to wallboard or similar sheeting, but it may be used wherever a coating having a hard, yet'iexible vitreous finish is desired, and where the water-proof and weather-proof properties are considered of especial value.

While I have suggested the ingredients in ,the proportions stated, I do not wish to be point from where I -start to dip the wallboard,

ut desire that the scope of my method cover the gradual dipping or lowering of the wallboard fromiany pomt in the surface thereof, my principle being to create a flow upon the wallboard from the given direction or directions whereby to coat the surface and displace the air without restriction of the same, so that no resistance is offered to the perfect coating of the surface by the enamel.

In conclusion, it may be stated that Whatever variations may be made in the compounding or application of the novel enamel, as contemplated above, such changes will be to perfect and render the product susceptible to more uses, but vwill in no manner depart from the. principle of the invention as coveredin the appended claims.

1. The method of coating a sheet of firm material with an enamel, consisting of pouring a layer of the enamel into an open vessel, supporting the sheet in parallel relation to the surface of said layer,.1o'wering the sheet with one portion of its area upon said layer by bending the sheet, and gradually lowering the balance of the sheet from said portion to progressively meet said layer until fully coated with the same.

2. The method of coating a sheet of firm material with an enamel, consisting of pouring a layer of the enamel into an open vessel,

lowering the sheet with the medial portion of its area u n said layer, and gradually lowering the alance of the sheet from said portion to progressively meet said layer until fully coated with the same.

3. The method of coating a sheet of firm material with an enamel, consisting of pouring a layer of the enamel into an open vessel, lowering the sheet with one portion of its area intermediate its ends upon said layer, maintaining such portion depressed by the agency of a weight and gradually lowering the balance of the sheet from said portion to progressively meet said layer until fully coated with the same.

4., The method of coating a sheet of firm material with. an enamel, consisting of pour vous? 

